#!/usr/bin/perl -w
#
# mutt-fetchbug, extensively based off of
#       mutt-notmuch - notmuch (of a) helper for Mutt
#
#       Copyright: © 2011 Stefano Zacchiroli <zack@upsilon.cc>
#       License: GNU General Public License (GPL), version 3 or above
#
# Differences between mutt-notmuch and mutt-fetchbug are
#       Copyright: © 2012 Ryan Kavanagh <rak@debian.org>
#       License: GNU General Public License (GPL), version 3 or above
#
# See the bottom of this file for more documentation.
# A manpage can be obtained by running "pod2man mutt-fetchbug > mutt-fetchbug.1"

use strict;
use warnings;

use File::Path;
use Getopt::Long;
use Pod::Usage;

# search($btsmbox, $query)
# Fetch bugs matching $query with bts; store results in $btsmbox
sub search($$) {
    my ($btsmbox, $query) = @_;

    system("bts --cache-mode=mbox cache $query"
	   . " && ln -fs ~/.cache/devscripts/bts/$query.mbox $btsmbox");
}

sub search_action($$@) {
    my ($interactive, $btsmbox, @params) = @_;

    if (! $interactive) {
	fetch($btsmbox, join(' ', @params));
    } else {
	my $query = "";
	my $done = 0;
	while (! $done) {
	    print "bug number ('?' for man): ";
	    chomp($query = <STDIN>);
	    if ($query eq "?") {
		system("man bts");
	    } elsif ($query eq "") {
		$done = 1;	# quit doing nothing
	    } else {
		search($btsmbox, $query);
		$done = 1;
	    }
	}
    }
}

sub die_usage() {
    my %podflags = ( "verbose" => 1,
		    "exitval" => 2 );
    pod2usage(%podflags);
}

sub main() {
    my $btsmbox = "$ENV{HOME}/.cache/mutt_btsresults";
    my $interactive = 0;
    my $help_needed = 0;

    my $getopt = GetOptions(
	"h|help" => \$help_needed,
        "o|output-mbox=s" => \$btsmbox,
	"p|prompt" => \$interactive);
    if (! $getopt || $#ARGV < 0) { die_usage() };
    my ($action, @params) = ($ARGV[0], @ARGV[1..$#ARGV]);

    if ($help_needed) {
	die_usage();
    } elsif ($action eq "search" && $#ARGV == 0 && ! $interactive) {
	print STDERR "Error: no search term provided\n\n";
	die_usage();
    } elsif ($action eq "search") {
	search_action($interactive, $btsmbox, @params);
    } else {
	die_usage();
    }
}

main();

__END__

=head1 NAME

mutt-fetchbug - 'bts show' frontend for Mutt

=head1 SYNOPSIS

=over

=item B<mutt-fetchbug> [I<OPTION>]... search [I<SEARCH-TERM>]...

=back

=head1 DESCRIPTION

mutt-fetchbug is a frontend to the 'bts show' command (Debian package:
devscripts) designed to fetch bugs and place them in a predefined mbox. The
search term should typically be a bug number.

=head1 OPTIONS

=over 4

=item -o DIR

=item --output-mbox DIR

Store search results as (symlink) mbox MBOX. Beware: MBOX will be overwritten.
(Default: F<~/.cache/mutt_btsresults/>)

=item -p

=item --prompt

Instead of using command line search terms, prompt the user for them (only for
"search").

=item -h

=item --help

Show usage information and exit.

=back

=head1 INTEGRATION WITH MUTT

mutt-fetchbug can be used to integrate 'bts show' with the Mutt mail user agent
(unsurprisingly, given the name). To that end, you should define the following
macros in your F<~/.muttrc> (replacing F<~/bin/mutt-fetchbug> for the actual
location of mutt-fetchbug on your system):

    macro index <F7> \
        "<enter-command>unset wait_key<enter><shell-escape>~/bin/mutt-fetchbug --prompt search<enter><change-folder-readonly>~/.cache/mutt_btsresults<enter><enter-command>set wait_key<enter>" \
        "fetch bug(s) (using bts show)"

The macro (activated by <F7>) will prompt the user for a bug number and then
jump to a temporary mbox showing the fetched bug.

=head1 SEE ALSO

mutt(1), bts(1)

=head1 AUTHOR

mutt-fetchbug is extensively based off of 'mutt-notmuch', which is
Copyright: (C) 2011 Stefano Zacchiroli <zack@upsilon.cc>.

All differences between mutt-fetchbug and mutt-notmuch are
Copyright (C) 2012 Ryan Kavanagh <rak@debian.org>

License: GNU General Public License (GPL), version 3 or higher

=cut